The present invention relates to an improved remote control security system having a remote control unit, a receiving unit, and an operation unit connected to the receiving unit for activating or deactivating the alarm function of the security system . A combination code having a basic code and two sets of remedy codes is issued by an encoder. When the receiver receives the combination code signal from the remote control unit, a decoder compares the basic code and remedy codes produced by itself with the basic code and two sets of the remedy code of the code signal and, if the codes comparison matches, the decoder sends a control signal to the operation unit.
Luxury cars are easily spotted and often are stolen by burglars in big cities, so security systems or burglar proof devices of various kinds for automobiles have been designed and mounted onto those vehicles.
The basic burglar proof devices have an emitter which issues a fixed code, and a receiver mounted in an automobile for receiving the emitted code and making comparison therewith. If the two codes match, an alarm system is then automatically set or removed. However, a burglar holding a signal receiver and positioned in the vicinity of an automobile can decode the fixed code so that the burglar can remove the alarm system and steal the car with ease later.
Another prior art which has been developed to overcome the above cited problem is an alarm system which is not equipped with a fixed code but a variable one. However, the variable code is comprised of two sets of code, i.e., a fixed basic code and a variable code in combination. The variable code is produced constantly by a code generator. Although, the code is varible every time, the burglar can still detect the code by receiving codes produced while the user is holding down the button. It is more difficult to capture the code in this manner but it is still possible.
To overcome the above cited problems, the present inventor has provided a further improved alarm system for an automobile so that the issued signal will not be detected with ease.